Buick Lesabre computer error codes

I have an '88 Buick LeSabre which is running rough. I had the car put on the computer and the printout came back with these error codes:

Vehicle scanned: 1988 Buick LeSabre C=3.8L PFI (3800)

Diag. Trouble codes

History Code 22
Throttle Position Sensor (TPS) Signal voltage is too low

Current code 23
Manifold Air Temp (MAT) Sensor Signal too low

History Code 23
Manifold Air Temp (MAT) Sensor Signal too low

Current Code 41
Camshaft Sensor Loss of Signal

History Code 41
Camshaft Sensor Loss of Signal

History Code 48
Misfire Symptom

Let me know what is involved with this repair. I will change out the sensors in question. I would appreciate knowing what snags I may run into beforehand. I will have the tools and the repair manuals on hand when I do this repair.

Thanks!

Chris